Generating method and playing method of multimedia file, multimedia file generation apparatus and multimedia file playback apparatus

ABSTRACT

A generating method and a playing method of multimedia file, a multimedia file generation apparatus and a multimedia file playback apparatus are provided. The playing method of multimedia file includes following steps. A multimedia file including a panoramic video associated with a timeline is received. A first data track of the multimedia file is extracted to obtain object positions of the first image object in the panoramic video with respect to the timeline. When playing the panoramic video, an icon corresponding to the first image object is displayed in a display frame of a screen. In response to detecting a selection operation performed on the icon, a field of view (FoV) for playing the panoramic video is determined according to a first object position recorded in the first data track, and display frames including the first image object are played based on the determined FoV.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 107127500, filed on Aug. 7, 2018. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND Technical Field

The disclosure relates to a video playback technic, particularly to agenerating method and a playing method of multimedia file, a multimediafile generation apparatus and a multimedia file playback apparatus.

Related Art

A panorama camera and a 360-degree panorama video are getting popular inthese days, and the user can view the 360-degree panorama video (alsocalled as a panorama video) by using a computer monitor. Throughcapturing a plurality of images using a plurality lens according to thedifferent photographing angle and performing image stitching processing,the 360-degree panorama video is able to be produce, which can providethe user with an immersive effect.

Actually, the user can merely view part of content of the 360-degreescene when the user views the 360-degree panorama video by using thecomputer monitor. The user may need to adjust the field of view (FOV)for playing the 360-degree panorama video so as to see the differentcorners in the 360-degree scene. Therefore, the user may need tomanually adjust the FOV to search an object of interest, which greatlyreduces the convenience in viewing a 360-degree panorama video. Inaddition, since the performance of general consumer electronics islimited, it is hard for the general consumer electronics to performimage object recognition and image object tracking on the 360-degreepanorama video in real-time. Hence, the user may need to manually adjustthe FOV frequently in response to movement of the object of interestwhen the user only wants to view a specific object of interest.

SUMMARY

In view of the above, embodiments of the disclosure propose a generatingmethod of multimedia file and a multimedia file generation apparatus,which can generate a multimedia file including a 360-degree panoramavideo and recording position information of the image object byestablishing a specific data track for the multimedia file based on theposition information of the image object.

Further, embodiments of the disclosure propose a playing method ofmultimedia file and a multimedia file playback apparatus, which canobtain position information of the image object from the specific datatrack of the multimedia file so as to dynamically adjust the view angleaccording to the position information of the image object interested bythe user.

In one embodiment of the disclosure, a generating method of multimediafile is provided and is applicable to a multimedia file generationapparatus, and the method includes following steps. A panorama videoassociated with a timeline is obtained, wherein the panorama videoincludes at least one image object. A plurality of object positions ofthe at least one image object are obtained, and the object positions arecorresponding to the timeline. The object positions are manufacturedinto an object position file. At least one data track of a multimediafile is generated according to the object position file to produce themultimedia file including the panorama video and recording the objectpositions.

In one embodiment of the disclosure, a multimedia file generationapparatus including a storage device and a processor is provided. Thestorage device records a plurality of modules, and the processor iscoupled to the storage device and is configured to execute the modules.The modules include an video obtaining module, a position obtainingmodule, a file generation module and a file embedding module. The videoobtaining module obtains a panorama video associated with a timeline,wherein the panorama video comprises at least one image object. Theposition obtaining module obtains a plurality of object positions of theat least one image object corresponding to the timeline. The filegeneration module manufactures the object positions into an objectposition file. The file embedding module generates at least one datatrack of a multimedia file according to the object position file toproduce the multimedia file including the panorama video and recordingthe object positions.

In one embodiment of the disclosure, a playing method of multimedia fileis provided and is applicable to a multimedia file playback apparatus,and the method includes following steps. A multimedia file including apanorama video associated with a timeline is received. A first datatrack of the multimedia file is extracted to obtain a plurality of firstobject positions of a first image object corresponding to the timeline.An icon of the first image object is displayed in frames displayed bythe screen when playing the panorama video. In response to detecting aselection operation performed on the icon, a field of view (FOV) forplaying the panorama video is determined according to the first objectpositions recorded by the first data track, and the frames including thefirst image object is played based on the determined FOV.

In one embodiment of the disclosure, a multimedia file playbackapparatus including a screen, a storage device and a processor isprovided. The storage device records a plurality of modules, and theprocessor is coupled to the screen and the storage device and isconfigured to execute the modules. The modules include a video receivingmodule, a data track extracting module, an interface providing moduleand a video playback module. The video receiving module receives amultimedia file including a panorama video associated with a timeline.The data track extracting module extracts a first data track of themultimedia file to obtain a plurality of first object positions of afirst image object corresponding to the timeline. The interfaceproviding module displays an icon of the first image object in framesdisplayed by the screen when playing the panorama video. In response todetecting a selection operation performed on the icon, the videoplayback module determines a FOV for playing the panorama videoaccording to the first object positions recorded by the first data trackand plays the frames including the first image object based on thedetermined FOV.

Based on the above, the multimedia file generation apparatus mayestablish a specific data track of the multimedia file according to theobject positions of the image objects shown in the panorama video.Hence, the multimedia file playback apparatus may obtain the objectpositions of the image objects located in the panorama video from thespecific data track of the multimedia file when playing the panoramavideo, and thus the FOV can be dynamically determined according to theobject positions of the image objects. Such that, the user does not needto adjust the FOV for playing the panorama video frequently, but thespecific image object in the panorama video still can be aimed for beviewed by the user.

To make the above features and advantages of the disclosure morecomprehensible, several embodiments accompanied with drawings aredescribed in detail as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a multimedia file generationapparatus according to one embodiment of the disclosure.

FIG. 2 is a flowchart illustrating a generating method of a multimediafile according to an embodiment of the disclosure.

FIG. 3A and FIG. 3B are schematic diagrams illustrating a plurality ofobject positions corresponding to a plurality of time zones according toone embodiment of the disclosure.

FIG. 4 is a schematic diagram illustrating an example of an objectposition file according to one embodiment of the disclosure.

FIG. 5 is a schematic diagram illustrating a structure of a multimediafile according to one embodiment of the disclosure.

FIG. 6 is a block diagram illustrating a multimedia file playbackapparatus according to one embodiment of the disclosure.

FIG. 7 is a flowchart illustrating a playing method of a multimedia fileaccording to an embodiment of the disclosure.

FIG. 8A and FIG. 8B are exemplary schematic diagrams of playing themultimedia file according to an embodiment of the disclosure.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

Some embodiments of the disclosure will be hereinafter described indetail with reference to the accompanying drawings. In the followingdescription, the same reference numerals in different drawings representthe same or similar elements. These embodiments are only a part of thedisclosure and do not disclose all of the possible implementations ofthe disclosure.

FIG. 1 is a block diagram illustrating a multimedia file generationapparatus according to one embodiment of the disclosure. It should,however, be noted that this is merely an illustrative example and thedisclosure is not limited in this regard. All components of themultimedia file generation apparatus and their configurations are firstintroduced in FIG. 1. The functionalities of the components aredisclosed with FIG. 2 in more detail in the subsequent embodiments.

Please referring to FIG. 1, the multimedia file generation apparatus 10may be any electronic apparatus having computing capability, such as adesk computer, a notebook computer, a server and so on, which is notlimited in the disclosure. The multimedia file generation apparatus 10includes a processor 110 and a storage device 120, and thefunctionalities of the processor 110 and the storage device 120 aredescribed below.

The storage device 120 is, for example, a fixed or movable random accessmemory (RAM) in any form, a read-only memory (ROM), a flash memory, ahard disc, other similar devices, or a combination of these devices. Inthe present embodiment, the storage device 120 is configured to record avideo obtaining module 121, a position obtaining module 122, a filegenerating module 123 and a file embedding module 124.

The processor 110 is coupled to the storage device 120 and would beconfigured to execute the proposed generating method, and may be, forexample, a central processing unit (CPU) or other programmable devicesfor general purpose or special purpose such as a microprocessor and adigital signal processor (DSP), a programmable controller, anapplication specific integrated circuit (ASIC), a programmable logicdevice (PLD), other similar devices, a combination of above-mentioneddevices or integrated circuits.

In the present embodiment, the modules recorded in the storage device120 may be, for example, computer program and are able to be accessed bythe processor 110, such that the proposed generating method ofmultimedia file can be implemented accordingly.

FIG. 2 is a flowchart illustrating a generating method of multimediafile according to an embodiment of the disclosure, where the flow inFIG. 2 may be implemented by the multimedia file generation apparatus 10in FIG. 1. Referring to both FIG. 1 and FIG. 2, detailed steps of thegenerating method of multimedia file in this embodiment is describedwith reference to the components in the multimedia file generationapparatus 10 as follows.

In step S201, the video obtaining module 121 may obtain a panorama videoassociated with a timeline, wherein the panorama video comprises atleast one image object. Herein, the video obtaining module 121 mayobtain the panorama video from an image capturing module (not shown) ofthe multimedia file generation apparatus 10 or from the other electronicdevices. The panorama video composed of video frames corresponding todifferent time stamps on the timeline may be called as 360-degreepanorama video as well, and the video frames are 360-degree imagesstored in a specific format. The specific format is, for example,Equiangular format, etc. It should be noted that, in the embodiments ofthe disclosure, the panorama video includes at least one image objectgenerated by photographing at least one real object. That is, the imageobject is shown in the video frames of the panorama vide. The imageobject in the panorama video may be human face, for example, or may beother kinds of image objects. The disclosure is not limited in thisregard.

In the step S202, the position obtaining module 122 obtains a pluralityof object positions of the at least one image object corresponding tothe timeline. In one embodiment, the object positions of the imageobject may be generated through viewing via human eyes and then manuallyediting by a video editor. Namely, through viewing the panorama videovia human eyes and then manually marking up the object positions of theimage object by the video editor, the position obtaining module 122 mayobtain a plurality of object positions of the image object in a stereocoordinate system. Alternatively, in one embodiment, the objectpositions of the image object may be generated automatically throughimage object detection and recognition algorithms of image processingtechnique. In other words, through tracking the image object by usingimage object detection and recognition algorithms, the positionobtaining module 122 may obtain a plurality of object positions of theimage object in the stereo coordinate system respectively withindifferent time zones. The object positions of the image object may be aspherical coordinates of a spherical coordinate system, for example.

In one embodiment, the object positions of the image object respectivelycorrespond to a plurality of time zones on the timeline. That is, theobject positions of the image object may be sampled according to fixedor unfixed time intervals. Please referring to FIG. 3A, FIG. 3A is sschematic diagram illustrating a plurality of object positionscorresponding to a plurality of time zones according to one embodimentof the disclosure. For one image object, the position obtaining module122 may obtain the object position (r1, θ1, ϕ1) corresponding to thetime interval P1, the object position (r2, θ2, ϕ2) corresponding to thetime interval P2, and the object position (r3, θ3, ϕ3) corresponding tothe time interval P3. It should be noted that, the time length of thetime interval P1-P3 may be the same or different with each other. Thedisclosure is not limited in this regard.

In addition, in one embodiment, the number of the panorama video may betwo or more than two. For instance, at least one of the image object inthe panorama video may include a first image object and a second imageobject. Accordingly, the object positions corresponding to the timelinemay include a plurality of first object positions of the first imageobject and a plurality of seconds object position of the second imageobject. Please referring to FIG. 3B, FIG. 3B is a schematic diagramillustrating a plurality of object positions corresponding to aplurality of time zones according to one embodiment of the disclosure.For the first image object, the position obtaining module 122 may obtainthe object position (r4, θ4, ϕ4) corresponding to the time interval P1and the object position (r5, θ5, ϕ5) corresponding to the time intervalP2. For the second image object, the position obtaining module 122 mayobtain the object position (r6, θ6, ϕ6) corresponding to the timeinterval P1 and the object position (r7, θ7, ϕ7) corresponding to thetime interval P2.

Next, return to the flow in FIG. 2, in step S203, the file generatingmodule 123 may manufacture the object positions into an object positionfile. The file generating module 123 may compile the object positionsrespectively corresponding to the time zones on the timeline as anobject position file by a predetermined file format. In one embodiment,the manner of generating the object position file may be similarly withthe manner of generating a video subtitle file. Please referring to FIG.4, FIG. 4 is a schematic diagram illustrating an example of an objectposition file according to one embodiment of the disclosure. The objectposition file 40 records the object positions of the two image objectsrespectively named as “Object name A” and “Object name B” in thepanorama video, and the object positions is recorded by using the fixedtime interval. The time interval is 1 second (sec) as example in FIG. 4,but the disclosure is not limited in this regard. For example, at timepoint 00:01.000, the object position of the image object named as“Object name A” is (r6, θ6, ϕ6), and the object position of the imageobject named as “Object name B” is (r7, θ7, ϕ7). At time point00:02.000, the object position of the image object named as “Object nameA” is (r8, θ8, ϕ8), and the object position of the image object named as“Object name B” is (r9, θ9, ϕ9).

In addition, in one embodiment, the file generating module 123 may mapthe object positions recorded as a plurality of stereo positioncoordinates into a plurality of two-dimension position coordinates, andthus record the two-dimension position coordinates in the objectposition file. Generally, the video frames in the panorama video arestored by mapping the panorama images into two-dimension images, such asstoring the panorama video by Equiangular format. The object positionsrecorded as the stereo position coordinates (e.g. spherical coordinates)may be mapped into the two-dimension position coordinates in thetwo-dimension coordinate system and be stored accordingly, such that thedata amount of the object position file may be reduced.

Afterward, in step S204, the file embedding module 124 may generate atleast one data track of a multimedia file according to the objectposition file to produce the multimedia file including the panoramavideo and recording the object positions. FIG. 5 is a schematic diagramillustrating a structure of a multimedia file according to oneembodiment of the disclosure. The multimedia file 50 includes a header50 and multimedia data 52, and the multimedia data 52 includesmultimedia data which may be classified into a plurality of data tracks.Namely, the multimedia file 50 may include a plurality of data tracks.The header 51 records description of the data tracks and the number ofthe data tracks, and the data tracks may include a video data track 521,an audio data track, a subtitle data track 523 and an object positiondata track 524. The video data track is configured for classifying thevideo data; the audio data track is configured for classifying the audiodata, and the different audio data tracks may refer to differentlanguages; the subtitle data track is configured for classifying thesubtitle data, and the different subtitle data tracks may refer todifferent languages.

In one embodiment, when the object position file includes the firstobject positions of the first image object and the second objectpositions of the second image object (such as the example shown in FIG.4), the file embedding module 124 may generate a first data trackcorresponding to the first image object and embed the first objectpositions (such as (r4, θ4, ϕ4), (r6, θ6, ϕ6), (r6, θ6, ϕ6) shown inFIG. 4) in the object position file into a first data track. On theother hand, the file embedding module 124 may generate a second datatrack corresponding to the second image object and embed the secondobject positions (such as (r5, θ5, ϕ5), (r7, θ7, ϕ7), (r9, θ9, ϕ9) shownin FIG. 4) in the object position file into a second data track. Thatis, the number of the object position data tracks is determinedaccording to the number of the image objects, and the object positionsof each image object are recorded by the corresponding object positiondata track. Namely, the different object position data tracks may referto the position information of the different image objects.

It should be noted that, compared with the conventional multimedia file,the multimedia file 50 further includes the object position data track524 configured for recording the object positions. The file embeddingmodule 124 may establish at least one data track (i.e. the objectposition data track 524) of the multimedia file 50 according to theobject position file. For example, in FIG. 4, the data in the objectposition file 40 is embedded into the object position data track 524 ofthe multimedia file 50. Herein, embedding the data into at least onedata track of the multimedia file 50 refers as embedding the data intothe data block of the at least one data track of the multimedia file 50.Further, the header 51 further records description of the at least oneobject position data track and the number of the at least one objectposition data track. Such that, the player for playing the multimediafile 50 not only may play the panorama video of the multimedia file 50but also may obtain the position information of the image objectslocated in the panorama video.

After describing how to generate a multimedia file recording the objectpositions of the image objects located in the panorama video, thefollowing embodiments are provided to describe how to play the panoramavideo according to the multimedia file in the disclosure.

FIG. 6 is a block diagram illustrating a multimedia file playbackapparatus according to one embodiment of the disclosure. It should,however, be noted that this is merely an illustrative example and thedisclosure is not limited in this regard. All components of themultimedia file playback apparatus and their configurations are firstintroduced in FIG. 6. The functionalities of the components aredisclosed with FIG. 7 in more detail in the subsequent embodiments.

Please referring to FIG. 6, the multimedia file playback apparatus 60may be any electronic apparatus having computing capability anddisplaying capability, such as a desk computer, a notebook computer, asmart phone, a tablet and so on, which is not limited in the disclosure.The multimedia file playback apparatus 60 includes a processor 610, astorage device 620 and a screen 630.

The storage device 620 is, for example, a fixed or movable random accessmemory (RAM) in any form, a read-only memory (ROM), a flash memory, ahard disc, other similar devices, or a combination of these devices. Inthe present embodiment, the storage device 620 is configured to record avideo receiving module 621, a data track extracting module 622, aninterface providing module 623 and a video playback module 624. In oneembodiment, the above module may be implemented by a software player.

The processor 610 is coupled to the storage device 620 and would beconfigured to execute the proposed playing method, and may be, forexample, a central processing unit (CPU) or other programmable devicesfor general purpose or special purpose such as a microprocessor and adigital signal processor (DSP), a programmable controller, anapplication specific integrated circuit (ASIC), a programmable logicdevice (PLD), other similar devices, a combination of above-mentioneddevices or integrated circuits.

The screen 630 is configured to display the frames outputted by themultimedia file playback apparatus 60 for user. In the embodiment, themultimedia file playback apparatus 60 may be, for example, a liquidcrystal display (LCD), a light-emitting diode (LED) display, a fieldEmission display (FED) or other kinds of the displays.

In the present embodiment, the modules recorded in the storage device620 may be computer program for example and are able to be accessed bythe processor 610, such that the proposed playing method of multimediafile can be implemented accordingly.

FIG. 7 is a flowchart illustrating a playing method of a multimedia fileaccording to an embodiment of the disclosure, where the flow in FIG. 7may be implemented by the multimedia file playback apparatus 60 in FIG.6. Referring to both FIG. 6 and FIG. 7, detailed steps of the playingmethod of multimedia file in this embodiment is described with referenceto the components in the multimedia file playback apparatus 60 asfollows.

In step S701, the video receiving module 621 may receive a multimediafile including a panorama video associated with a timeline. The videoreceiving module 621 may receive the multimedia file including thepanorama video via wireless network or wired network, or may read themultimedia file from the storage device 620 or other external storagedevice. In step S702, the data track extracting module 622 may extract afirst data track of the multimedia file to obtain a plurality of firstobject positions of a first image object corresponding to the timeline.The data track extracting module 622 may demultiplex the multimedia fileto obtain multimedia data in each of the data tracks. In one embodiment,the data tracks of the multimedia file may include a video data track,an audio data track, a subtitle data track and an object position datatrack. The data track extracting module 622 may extract the multimediadata classified in the object position data track from the multimediafile, and the multimedia data classified in the object position datatrack includes a plurality of a first object positions of the firstimage object corresponding to the timeline in the panorama video. Theobject positions in the object position data track have been illustratedbefore and would not be describe again redundantly. Similarly, the datatrack extracting module 622 may also extract the video data classifiedin the video data track from the multimedia file, and may decode thevideo data to obtain the video frames of the panorama video.

Next, in step S703, the interface providing module 623 may display anicon of the first image object in the frames displayed by the screen 610when playing the panorama video. That is, the interface providing module623 may provide a user interface of the player which includes a framedisplay zone and a playback controlling bar. It should be noted that,the interface providing module 623 may be aware of the number of theimage objects tagged previously in the video content of the panoramavideo by analyzing the number of the object position data track in theheader (e.g. header 51 shown in FIG. 5) of the multimedia file. Hence,the interface providing module 623 may display the icons of the imageobjects tagged previously in the frames displayed by the screen 610while playing the panorama video. The said icons may be an interactiveobject in any shapes, and the name or the representing pattern of theimage objects may be shown in the icons, so as to immediately guide theuser about key element of the panorama video. Further, each of the iconsmay be displayed at the edge of the playback frame or may be displayedin the playback controlling bar of the player.

Next, the processor 610 may continually detect whether the user selectsany icons to detect a selection operation performed on one icon nu theuser. Hence, in step S704, in response to detecting a selectionoperation performed on the icon, the video playback module determines aFOV for playing the panorama video according to the first objectpositions recorded by the first data track and plays the framesincluding the first image object based on the determined FOV. That is,when the user selects a icon corresponding to the first image object,the video playback module 624 may be aware of the current objectposition of the first image object in the panorama video from the objectposition data track. Afterward, the video playback module 624 maydetermine the FOV according to current object position of the firstimage object, and the display frame would be moved from a predeterminedregion to a first region where the first image object located in, suchthat the user may view the selected key object immediately.

It should be noted that, the first object position of the selected firstimage object may vary. Take FIG. 3B as example, the first objectposition of the first image object may be changed from (r4, θ4, ϕ4) to(r6, θ6, ϕ6). IF the FOV is not adjusted, the first image object maydisappear from the display frame. In one embodiment, the video playbackmodule 624 may switch the FOV according to the first object positionwhich has been change in response to identifying a change of the firstobject positions.

Take FIG. 3B as example, in response to that the first object positionof the first image object has been changed from (r4, θ4, ϕ4) into (r6,θ6, ϕ6), the video playback module 624 may switch the playback FOV froma first FOV to a second FOV. Accordingly, the display frame may bevaried from the first region to the second region where the first imageobject located in. That is, the video playback module 624 may play thefirst region of the panorama video according to the first FOV within thetime interval P1, and then play the second region of the panorama videoaccording to the second FOV within the time interval P2. Such that, theuser can continually view the selected object without manually adjustingthe FOV.

It should be noted that, the number of the image objects may be two ormore than two. In one embodiment, except for extracting a first datatrack of the multimedia file, the data track extracting module 622 mayfurther extract a second data track of the multimedia file to obtain aplurality of second object positions of the second image objectcorresponding to the time line in the panorama video. Hence, whenplaying the panorama video, the interface providing module 623 may alsodisplay another icon corresponding to the second image object in thedisplay frame displayed by the screen 610. Such that, in response todetecting a selection operation performed on the another icon, the videoplayback module 624 may switch the FOV according to the second objectpositions recorded by the second data track and plays the framesincluding the second image object based on the switched FOV.

For example, FIG. 8A and FIG. 8B are exemplary schematic diagrams ofplaying the multimedia file according to an embodiment of thedisclosure. Please referring to FIG. 8A, when the multimedia fileplayback apparatus 60 plays the multimedia file of the disclosure, thepanorama video is played along with the timeline. The user can adjustthe FOV for playing the panorama video by performing the operation onthe virtual controlling button 82. The multimedia file playbackapparatus 60 may obtain the description of the object position datatrack and the number of the object position data track from the headerof the multimedia file, so as to be aware of the object name or thenumber of the image objects tagged previously. In the present example,assuming the number of the image objects tagged previously is 3, thus,the multimedia file playback apparatus 60 may display three icons I1-I3in the frame 80 and the three icons I1-I3 respectively show the name‘A’, ‘B’, ‘C’ of the three image objects.

Assuming the user wants to view the image object 83 (i.e. key person A)corresponding to the icon I1, the multimedia file playback apparatus 60may determine the FOV for playing panorama video according to the objectpositions of the image object 83 recorded in the object position datatrack in response to detecting the selection operation performed on theicon I1 by the user, so as to play the frame 80 including the imageobject 83 according to the determined FOV. In the present example, theselected image object 83 is located in the middle of the frame 80.Afterward, assuming the user wants to view the image object 84 (i.e. keyperson B) corresponding to the icon I2, the multimedia file playbackapparatus 60 may switch the FOV for playing panorama video according tothe object positions of the image object 84 recorded in the objectposition data track in response to detecting the selection operationperformed on the icon I2 by the user, so as to play the frame 86including the image object 84 according to the switched FOV. In thepresent example, after switching the FOV, the selected image object 84is located in the middle of the frame 86.

In summary, in the embodiments of the disclosure set above, themultimedia file including the panorama video further includes an objectposition data track for recording the position information of the imageobjects. The multimedia file generation apparatus embeds the objectpositions of the image object into the multimedia file, such that themultimedia file playback apparatus can obtain the object positions of aspecific image object immediately while playing the panorama video.Based on above, the powerful computing capability for performing imageobject recognition and tracking is not necessary for the multimediaplayback apparatus of the user. In addition, after the user selects animage object of interest, the multimedia file playback apparatus canadjust the FOV dynamically according to the object positions of theimage object, to accomplish the playback function capable of tracking aspecific image object. Therefore, the user may not need to adjust theFOV manually to view an image object of interest, such that theconvenience of viewing the 360-degree panorama video is greatly upgrade.The disclosure would immediately guide the user about all key elementsin a panoramic video so that the user would be able to view thepanoramic video in an intuitive and speedy manner.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of thedisclosed embodiments without departing from the scope or spirit of thedisclosure. In view of the foregoing, it is intended that the disclosurecover modifications and variations of this disclosure provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. A generating method of multimedia file,applicable to a multimedia file generation apparatus, and comprising:obtaining a panorama video associated with a timeline, wherein thepanorama video comprises at least one image object, the panorama videois composed of video frames respectively corresponding to different timestamps on the timeline; obtaining a plurality of object positions of theat least one image object corresponding to the timeline, wherein the atleast one image object comprises a first image object, the objectpositions corresponding to the timeline comprises a plurality of firstobject positions of the first image object, and the first objectpositions within different time zones are sampled according to a timeinterval; manufacturing the object positions into an object positionfile; and generating at least one data track of a multimedia fileaccording to the object position file to produce the multimedia fileincluding the panorama video and recording the object positions, whereinthe multimedia file comprises the at least one data track recording theobject positions, wherein the multimedia file comprises a header and aplurality of data tracks, the data tracks comprise a video data trackand at least one object position data track configured for recording theobject positions, and the header records description of the at least oneobject position data track and the number of the at least one objectposition data track.
 2. The generating method of multimedia fileaccording to claim 1, wherein the at least one image object comprises asecond image object, the object positions corresponding to the timelinecomprises a plurality of second object positions of the second imageobject, and the step of generating the at least one data track of themultimedia file according to the object position file comprises:embedding the first object positions in the object position file into afirst data track; and embedding the second object positions in theobject position file into a second data track.
 3. The generating methodof multimedia file according to claim 1, wherein the object positions ofthe at least one image object respectively correspond to a plurality oftime zones on the timeline.
 4. The generating method of multimedia fileaccording to claim 1, wherein the step of manufacturing the objectpositions into the object position fil comprises: mapping the objectpositions recorded as a plurality of stereo position coordinates into aplurality of two-dimension position coordinates, and recording thetwo-dimension position coordinates in the object position file.
 5. Amultimedia file generation apparatus, comprising: a storage device,recording a plurality of modules; a processor, coupled to the storagedevice, and configured to execute the modules to: obtain a panoramavideo associated with a timeline, wherein the panorama video comprisesat least one image object, the panorama video is composed of videoframes respectively corresponding to different time stamps on thetimeline; obtain a plurality of object positions of the at least oneimage object corresponding to the timeline, wherein the at least oneimage object comprises a first image object, the object positionscorresponding to the timeline comprises a plurality of first objectpositions of the first image object, and the first object positionswithin different time zones are sampled according to a time interval;manufacture the object positions into an object position file; andgenerate at least one data track of a multimedia file according to theobject position file to produce the multimedia file including thepanorama video and recording the object positions, wherein themultimedia file comprises the at least one data track recording theobject positions, wherein the multimedia file comprises a header and aplurality of data tracks, the data tracks comprise a video data trackand at least one object position data track configured for recording theobject positions, and the header records description of the at least oneobject position data track and the number of the at least one objectposition data track.
 6. The multimedia file generation apparatusaccording to claim 5, wherein the at least one image object comprises asecond image object, the object positions corresponding to the timelinecomprises a plurality of second object positions of the second imageobject, wherein the processor is configured to embed the first objectpositions in the object position file into a first data track and embedthe second object positions in the object position file into a seconddata track.
 7. The multimedia file generation apparatus according toclaim 5, wherein the object positions of the at least one image objectrespectively correspond to a plurality of time zones on the timeline. 8.The multimedia file generation apparatus according to claim 5, whereinthe processor is configured to map the object positions recorded as aplurality of stereo position coordinates into a plurality oftwo-dimension position coordinates, and to record the two-dimensionposition coordinates in the object position file.
 9. A playing method ofmultimedia file, applicable to a multimedia file playback apparatus, andcomprising: receiving a multimedia file comprising a panorama videoassociated with a timeline, the panorama video is composed of videoframes respectively corresponding to different time stamps on thetimeline; extracting a first data track of the multimedia file to obtaina plurality of first object positions of a first image objectcorresponding to the timeline, wherein the first object positions withindifferent time zones are sampled according to a time interval;displaying an icon of the first image object in frames displayed by ascreen when playing the panorama video; and in response to detecting aselection operation performed on the icon, determining a field of view(FOV) for playing the panorama video according to the first objectpositions recorded by the first data track and playing the framesincluding the first image object based on the determined FOV, whereinthe multimedia file comprises the first data track recording the firstobject positions, wherein the multimedia file comprises a header and aplurality of data tracks, the data tracks comprise a video data trackand at least one object position data track configured for recording theobject positions, and the header records description of the at least oneobject position data track and the number of the at least one objectposition data track.
 10. The playing method of multimedia file accordingto claim 9, wherein the step of in response to detecting the selectionoperation performed on the icon, determining the FOV for playing thepanorama video according to the first object positions recorded by thefirst data track comprises: switching the FOV in response to identifyinga change of the first object positions.
 11. The playing method ofmultimedia file according to claim 9, further comprising: extracting asecond data track of the multimedia file to obtain a plurality of secondobject positions of a second image object corresponding to the timeline;and displaying another icon of the second image object in the framesdisplayed by the screen when playing the panorama video.
 12. The playingmethod of multimedia file according to claim 11, wherein the step ofafter the step of determining the FOV for playing the panorama videoaccording to the first object positions recorded by the first data trackin response to detecting the selection operation performed on the icon,the method further comprises: in response to detecting a selectionoperation performed on the another icon, switching the FOV according tothe second object positions recorded by the second data track andplaying the frames including the second image object based on theswitched FOV.
 13. A multimedia file playback apparatus, comprising: ascreen; a storage device, recording a plurality of modules; a processor,coupled to the screen and the storage device, and configured to executethe modules to: receive a multimedia file comprising a panorama videoassociated with a timeline, the panorama video is composed of videoframes respectively corresponding to different time stamps on thetimeline; extract a first data track of the multimedia file to obtain aplurality of first object positions of a first image objectcorresponding to the timeline, wherein the first object positions withindifferent time zones are sampled according to a time interval; displayan icon of the first image object in frames displayed by the screen whenplaying the panorama video; and in response to detecting a selectionoperation performed on the icon, determine a field of view (FOV) forplaying the panorama video according to the first object positionsrecorded by the first data track and play the frames including the firstimage object based on the determined FOV, wherein the multimedia filecomprises the first data track recording the first object positions,wherein the multimedia file comprises a header and a plurality of datatracks, the data tracks comprise a video data track and at least oneobject position data track configured for recording the objectpositions, and the header records description of the at least one objectposition data track and the number of the at least one object positiondata track.
 14. The multimedia file playback apparatus according toclaim 13, wherein the processor is configured to switch the FOV inresponse to identifying a change of the first object positions.
 15. Themultimedia file playback apparatus according to claim 13, wherein theprocessor is configured to extract a second data track of the multimediafile to obtain a plurality of second object positions of a second imageobject corresponding to the timeline, and to display another icon of thesecond image object in the frames displayed by the screen when playingthe panorama video.
 16. The multimedia file playback apparatus accordingto claim 15, wherein in response to detecting a selection operationperformed on the another icon, the processor is configured to switch theFOV according to the second object positions recorded by the second datatrack and to play the frames including the second image object based onthe switched FOV.